ThunderCats is an American animated television series that was produced by Rankin-Bass Animated Entertainment and Leisure Concepts debuting in 1985, based on the characters created by Tobin "Ted" Wolf. The series, for which Leonard Starr was the head writer, follows the adventures of a group of catlike humanoid aliens. The animation for the episodes was provided by the Japanese studio Pacific Animation Corporation, later acquired in 1989 to form Walt Disney Animation Japan. Season 1 of the show aired in 1985 (65 episodes), followed by a TV movie entitled ThunderCats – HO! in 1986. Seasons 2, 3, and 4 followed a new format of twenty episodes each, starting with a five-part story.